Suspension means for vertical shafts



1953 F. c. BAKER SUSPENSION MEANS FOR VERTICAL SHAF'TS Filed Oc v/////Aa:///////// INVENTOR. FREDERICK G. BAKER ATTORNEY Patented Jan. 20, 1953 UNITED STATES PATENT OFFICE SUSPENSION MEANS FOR VERTICAL SHAFTS.

Frederick C. Baker, Portland, Oreg.

Application October 23, 1950, Serial No. 191,639

1 Claim. 1

This invention relates to means adapted to support a shaft flexibly in a desired relative position in such manner that when the shaft is temporarily moved out of such desired position, by application of a temporary force, it will be automatically returned to the desired position when relieved of the application of such force.

I believe the most important use for the invention will be found in its adaptation for the suspension of vertical shafts and the like to which lighting fixtures are secured, and consequently my invention relates particularly to means for flexibly suspending a vertical shaft for lighting fixtures, and the invention will be described with reference to this particular important use, although other applications of the invention are not to be considered as excluded.

When lighting fixtures are suspended from the ceiling it is desirable that they be allowed a certain amount of freedom to swing, for example in the event that something inadvertently strikes against them, thus reducing the likelihood of their being damaged by such contact. Also it is important that thereupon they return to their original proper position with their shafts, by which they are suspended, exactly vertical.

Furthermore, when the fixtures are square or rectangular in design, as in the case particularly of many modern design lighting fixtures, where certain lines of the fixture are intended to be parallel to, or at some fixed angularity with respect to, the walls or to the architectural or decorative lines in the ceiling, then it is also very desirable that when such fixtures are temporarily disturbed, even to the extent of receiving partial rotation, they return to rest again in exactly the desired parallelism or angularity intended. A common and well recognized difiiculty with lighting fixtures of modern square design, having their shafts connected to ceiling mountings by customary types of universal joints, is that such fixtures in time, for one reason or another, become turned slightly, thus spoiling the general effect of such fixtures.

The particular object of the present invention accordingly is to provide an improved means for supporting a suspended vertical shaft which will permit a limited amount of universal swinging movement for the shaft but will cause the shaft always to return to rest in its original vertical position, and which will at the same time hold the shaft against any undesired partial and permanent rotation.

Another object of the present invention is to provide a permanent support for a shaft which will maintain the shaft normally in exact axial alignment with an element in the support while temporarily permitting the movement of the shaft into a position of axial angularity with respect to such element.

A further object of the invention is to provide a new and useful shaft supporting or suspending means which will be practical, simple and inexpensive to manufacture.

The way in which the above mentioned ob jects and incidental advantages are attained, and the manner in which the invention may be employed for the special purpose of providing a suspension support for a lighting fixture shaft such use being understood as a preferred embodiment of the invention-will be briefly described with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of a suspended lighting fixture in which my present invention is employed in the ceiling support for the upper end of the fixture shaft, the customary ceiling cap covering the support in the ceiling being omitted from the figure;

Fig. 2 is an elevation of the ceiling end of the fixture, drawn to a larger scale, with the ceiling cap in place;

Fig. 3 is a fragmentary vertical section taken through the center of the ceiling end of the fixture of Fig. 2, but drawn to a still larger scale;

Fig. 4 is an elevation of the ceiling support for the fixture with the ceiling cap removed;

Fig. 5 is a section on line 5-5 of Fig. 4, but showing the two cooperating elements of the shaft support moved apart axially for the sake of clarity.

Fig. 6 is an elevation of the two elements of Fig. 5 by themselves and in their same positions, a portion of the lower element shown broken away; and

Fig. 7 is a perspective view of the cooperating, specially formed, end of one of the two elements of Figs. 5 and 6, the ends of both elements being identical.

The present invention is closely related to the invention described in U. S. Letters Patent No. 2,470,282 issued under date of May 17, 1949, to Frederick C. Baker and Elbert Gary Spencer, entitled Mounting for Shafts and the Like, and reference should be made to this prior patent for a clearer understanding of the present invention.

Referring to Figs. 1, 2 and 3 of the accompanying drawings, the lighting fixture, the main portion of which is indicated by the reference character In in Fig. 1, is illustrated as being of 3 special modern square-shaped design, in which the square contour lines are intended to be maintained in parallelism with the respective walls of the room.

The main portion II] of the fixture is rigidly secured to the center vertical shaft H as usual, by which shaft the fixture is suspended at the desired distance below the ceiling I2, and through which the electric wires pass from the ceiling electric outlet to the light socket in the fixture.

The suspension support for the shaft I I, and the preferred form of my invention which is illustrated in the drawings, comprises two cooperating tubular members I3 and I4'(Figs. 3, 4, 5 and 6). These tubular members I3 and I4 preferably, though not necessarily, have the same corresponding diameters, in which case they can both be cut from the same piece of tubular shafting. It is necessary, however, when the support is made in the form shown in these figures, that the interior diameter of the lower member I3 be greater thanthe outside diameter of the fixture shaft II so that the latter will be able to swing to a limited extent in any direction withinthe lower member I3, the latter member being held stationary.

The tubular lower member I3 is stationary and is secured firmly to the ceiling, but is spaced a shortdistance below the ceiling as shown, being held by a pair of diametrically opposite brackets I5 and I5, the bottom ends of which are welded or otherwise rigidly attached to the lower member I3 and the upper ends of which have outwardly extending flanges provided with apertures for suitable screws for anchoring the brackets, and therewith the member I3, in placeon the ceiling.

The upper end of the fixture shaft I I is secured within the upper member It in any suitable manner. For example, a collar I6 is rigidly secured to the outside of the upper end of the fixture shaft II and rigidly secured Within the upper member It as shown in Figs. 3 and 5.

The abutting or engaging ends of the members I3 and Hlthus the upper end of the lower member I3 and the lower end of the upper member I l-are identical and each end comprises a pair of identical diametrically opposite v-shaped grooves. The pair of V-shaped grooves of each member extends to the end of the member from diametrically opposite points on the exterior surface and meet at diametrically opposite points to form two tips.

The exact manner in which the grooved engaging end of each member is formed can be best described with reference to Fig. 7. The two grooves i8, I9 and I8, It start from points I? and Il on the outside surface diametrically opposite each other and meet at points 29 and 2B which are diametrically opposite each other and turned 90 from the points H, H. The two bottom or vertex lines 2I and 2! of the two grooves would, if continued forward, as indicated by the broken lines in Fig. 7, meet at a point 22 on the axis of the member, and similarly the two ridge lines 23 and 23, terminating at the outer points 29 and 28' respectively, would, it continued inwardly, also meet at the same point 22' on the axis of the member. The distance of each of the points I'I, I1, 29, 26' from the center point 22 is equal, and the plane determined by the linesZIl, 22 and 28, 22 is perpendicular to the plane determined by the lines I1, 22 and I1, 22, and both planes intersect along the axis. of the member.

From this description of Fig. 7 it will be clear thatthe endsof thetwo members I3 and I I are cut in the same manner as the engaging ends of the shafts I 4 and I5 in previously mentioned Patent No. 2,470,282. Not only does this forming of the abutting ends of the two members insure perfect mating but it simplifies the cutting of the ends of the members.

Referring now particularly to Figs. 3 and 4, when the upper member I4 has been rigidly secured on the upper end of the fixture shaft II, with the axis of the upper member It in exact alignment with the axis of the shaft II, the lower end of the shaft I I, before the fixture is fastened thereto, is inserted through the lower member I3. It will now be apparent that when the securing brackets I5, I5 of the lower member I3 are fastened in place on the ceiling, with the axis of the lower member exactly vertical, the shaft II will be suspended in such manner that, while it may, if given a side thrust, swing to a limited extent in any direction, it will always quickly return to its exact normal position. Furthermore,

it cannot be rotated unless it can be raised sufficientlyso that the upper member I l will be entirely clear of the lower member I3, but, if this is done, the shaft will always return to exact vertical position and, if rotated when so raised, will be turned exactly or multiples thereof.

In assembling the fixture when the shaft I I has been inserted through the lower member I3, the shaft is inserted through the ceiling cap 24 (Figs. 2 and 3) and the main body portion Ill (Fig. l) of the fixture is secured to the shaft I I. (Or the main body of the fixture IB maybe first secured. to the shaft I! and the ceiling cap 23. and lower. member I3 slid over the upper end of the shaft before the upper end of the shaft is secured in the upper member it.) Then the lower member I3 is mounted in place on the ceiling, the conductor Wires extending through the shaft II being connected up to the outlet in the ceiling. Finally the ceiling cap 23 is secured in place in any suitable manner; for example, the ceiling cap may have a bottom collar 2&5 (Figs. 2 and 3) threaded on the inside and'adapted to be screwed on the lower threaded end of the lower member I3, or the collar 25 may be secured to the lower member I3 by set screws.

I claim:

A suspension device for a lighting fixture and the like comprising a pair of tubular members having their external and internal diameters sub,- stantially equal respectively, anidentically formed end on each member, each of saidends formedwith apair. of identical, diametrically opposite,, V-shaped grooves extending from diametrically,

opposite points on the outer surface of the member to. diametrically opposite tip points on the outer surface at the end of the member, the bottom vertex lines of said grooves located in. a,

plane with the axis ofthememoer, the ridge lines at said tip points formedbythe intersections of said grooves located in a plane with the: axis of the member and perpendicular to said;

first mentioned plane, whereby said ends of said ing the lower of said members inv said device, the

other member positioned above said lower mem her with its mating end down and constituting the upper of said members in said device, a suspen- Sion shaft for the lighting fixture, said shaft extending upwardly through said lower member and having an external diameter considerably less than the internal diameter of said lower member, and means rigidly securing the upper end of said shaft to said upper member and in axial alignment with said upper member, whereby said shaft and therewith the lighting fixture will be supported by said upper member in turn resting on said lower member, and whereby said shaft may be given a limited swing in said device, and, when raised slightly, may be rotated, but, when released, will again become vertical and be either in original position or rotated exactly 180 or multiples thereof from such original position.

FREDERICK C. BAKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

